Former Gov. Andrew Cuomo was ordered by New York's ethics commission Tuesday to give up millions of dollars a publisher paid him to write a book about his response to the coronavirus pandemic.

An attorney for Cuomo immediately called the action unconstitutional and promised a fight.

Cuomo was directed to turn over proceeds earned from “American Crisis: Leadership Lessons from the COVID-19 Pandemic” within 30 days under a resolution approved 12-1 by the Joint Commission on Public Ethics, according to multiple media reports.

The order came a month after the commission voted to rescind the ethics approval it had given Cuomo before he entered into the $5.1 million book deal.

“American Crisis" was published in October 2020, months before Cuomo resigned amid findings he sexually harassed 11 women.

The staff of the commission granted approval of the deal in July 2020, when his counsel told the commission that Cuomo agreed to not use any state personnel or resources to produce his book and that he would write it “entirely on his own time.” But complaints later surfaced that state property, resources and personnel were used to prepare, write, edit and publish the book.

Cuomo has acknowledged that state employees helped with tasks including editing the manuscript. But he’s claimed that those employees were volunteering.

“JCOPE’s actions today are unconstitutional, exceed its own authority and appear to be driven by political interests rather than the facts and the law," Cuomo attorney Jim McGuire said in a prepared statement. “Should they seek to enforce this action, we’ll see them in court.”

There was no immediate comment from the attorney general's office.

A separate state Assembly investigation released last month found evidence that Cuomo, who resigned in August, had his staff spend copious amounts of time on the project.

Junior and senior staff members told investigators they were asked to perform book tasks during their work day, including transcribing dictations, printing and delivering documents, and attending meetings with agents and publishers. One senior state official sent and received 1,000 emails about the book, the legislative report said.